I have been with Upwork for quite sometime now. And yet, until now, I still am not getting hired. I have updated my profile several times, gone through some posts as well as help topics to get my profile and proposal to standards, but I just am not getting hired.

You should add a video to your profile. Also I would go over your profile and try to cut down your intro paragraph by at least 40% the amount of text. Try sticking to two paragraphs max, if possible only one.